The binding interaction is further stabilized through extensive sugar and phosphate backbone interactions mediated by residues in the α-helix as well as a conserved loop within the β-sheet that forms a stabilized hairpin structure upon DNA recognition.
This study contributes to the understanding of gene-specific transcription by identifying a new promoter element that is contacted directly by an evolutionarily conserved loop within the largest subunit of the core RNA polymerase Bacterial promoters are recognized by RNA polymerase (RNAP) σ subunit, which specifically interacts with the −10 and −35 promoter elements.
Reticulons share little sequence homology except for the reticulon homology domain (RHD), a C-terminally located domain of ~ 200 amino acids composed of two short hairpin domains separated by a highly conserved loop-region.
Ricinus communis ricin toxin is a ribosome-inactivating protein (RIP) which irreversibly damages ribosomes by removal of a single adenine residue ("depurination") from a GAGA sequence in a universally conserved loop at the top of a stem in 28S rRNA, the so-called "sarcin/ricin loop" (SRL).
The importance of the conserved loop residue H479 for glycosylation was confirmed by site directed mutagenesis, while a change to alanine of the adjacent, non-conserved L480 had no effect.
The findings indicated the presence of a highly conserved loop structure which may act as a regulator involved in the stringent control of PCA biosynthesis by GacS/GacA signal transduction.
The apo ABA receptor contains an open ligand-binding pocket that is flanked by two highly conserved loops that serve as a gate and latch.
By contrast, the iGluR transmembrane segments have 4-fold symmetry and share a conserved pore loop architecture found in tetrameric voltage-gated ion channels.
That model had a conserved hairpin loop in the R-region, also found in the MLV LTR (Fig 3b) by MFOLD (Fig S4).
bHLH proteins are structurally and functionally characterised by a conserved domain containing a stretch of basic amino acids adjacent to two amphipathic α-helices separated by an interhelical loop.
